linux/drivers/base/dd.c, branch v5.12

driver core: Fix locking bug in deferred_probe_timeout_work_func()

2021-04-05T07:14:18Z

list_for_each_entry_safe() is only useful if we are deleting nodes in a linked list within the loop. It doesn't protect against other threads adding/deleting nodes to the list in parallel. We need to grab deferred_probe_mutex when traversing the deferred_probe_pending_list. Cc: stable@vger.kernel.org Fixes: 25b4e70dcce9 ("driver core: allow stopping deferred probe after init") Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20210402040342.2944858-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

driver core: clear deferred probe reason on probe retry

2021-03-23T14:13:43Z

When retrying a deferred probe, any old defer reason string should be discarded. Otherwise, if the probe is deferred again at a different spot, but without setting a message, the now incorrect probe reason will remain. This was observed with the i.MX I2C driver, which ultimately failed to probe due to lack of the GPIO driver. The probe defer for GPIO doesn't record a message, but a previous probe defer to clock_get did. This had the effect that /sys/kernel/debug/devices_deferred listed a misleading probe deferral reason. Cc: stable Fixes: d090b70ede02 ("driver core: add deferring probe reason to devices_deferred property") Reviewed-by: Andy Shevchenko Reviewed-by: Andrzej Hajda Signed-off-by: Ahmad Fatoum Link: https://lore.kernel.org/r/20210319110459.19966-1-a.fatoum@pengutronix.de Signed-off-by: Greg Kroah-Hartman

Revert "driver core: Reorder devices on successful probe"

2021-01-12T18:02:29Z

This reverts commit 5b6164d3465fcc13b5679c860c452963443172a7. Stephan reports problems with this commit, so revert it for now. Fixes: 5b6164d3465f ("driver core: Reorder devices on successful probe") Link: https://lore.kernel.org/r/X/ycQpu7NIGI969v@gerhold.net Reported-by: Stephan Gerhold Cc: Jonathan Hunter Cc: Rafael. J. Wysocki Cc: Thierry Reding Signed-off-by: Greg Kroah-Hartman

drivers core: Free dma_range_map when driver probe failed

2021-01-08T15:36:19Z

There will be memory leak if driver probe failed. Trace as below: backtrace: [<000000002415258f>] kmemleak_alloc+0x3c/0x50 [<00000000f447ebe4>] __kmalloc+0x208/0x530 [<0000000048bc7b3a>] of_dma_get_range+0xe4/0x1b0 [<0000000041e39065>] of_dma_configure_id+0x58/0x27c [<000000006356866a>] platform_dma_configure+0x2c/0x40 ...... [<000000000afcf9b5>] ret_from_fork+0x10/0x3c This issue is introduced by commit e0d072782c73("dma-mapping: introduce DMA range map, supplanting dma_pfn_offset "). It doesn't free dma_range_map when driver probe failed and cause above memory leak. So, add code to free it in error path. Fixes: e0d072782c73 ("dma-mapping: introduce DMA range map, supplanting dma_pfn_offset ") Cc: stable@vger.kernel.org Signed-off-by: Meng Li Link: https://lore.kernel.org/r/20210105070927.14968-1-Meng.Li@windriver.com Signed-off-by: Greg Kroah-Hartman

driver core: make driver_probe_device() static

2020-12-09T18:30:44Z

It's only used inside drivers/base/dd.c Signed-off-by: Julian Wiedmann Link: https://lore.kernel.org/r/20201123111938.18968-1-jwi@linux.ibm.com Signed-off-by: Greg Kroah-Hartman

driver core: Reorder devices on successful probe

2020-12-09T18:29:01Z

Device drivers usually depend on the fact that the devices that they control are suspended in the same order that they were probed in. In most cases this is already guaranteed via deferred probe. However, there's one case where this can still break: if a device is instantiated before a dependency (for example if it appears before the dependency in device tree) but gets probed only after the dependency is probed. Instantiation order would cause the dependency to get probed later, in which case probe of the original device would be deferred and the suspend/resume queue would get reordered properly. However, if the dependency is provided by a built-in driver and the device depending on that driver is controlled by a loadable module, which may only get loaded after the root filesystem has become available, we can be faced with a situation where the probe order ends up being different from the suspend/resume order. One example where this happens is on Tegra186, where the ACONNECT is listed very early in device tree (sorted by unit-address) and depends on BPMP (listed very late because it has no unit-address) for power domains and clocks/resets. If the ACONNECT driver is built-in, there is no problem because it will be probed before BPMP, causing a probe deferral and that in turn reorders the suspend/resume queue. However, if built as a module, it will end up being probed after BPMP, and therefore not result in a probe deferral, and therefore the suspend/resume queue will stay in the instantiation order. This in turn causes problems because ACONNECT will be resumed before BPMP, which will result in a hang because the ACONNECT's power domain cannot be powered on as long as the BPMP is still suspended. Fix this by always reordering devices on successful probe. This ensures that the suspend/resume queue is always in probe order and hence meets the natural expectations of drivers vs. their dependencies. Reported-by: Jonathan Hunter Acked-by: Rafael. J. Wysocki Signed-off-by: Thierry Reding Link: https://lore.kernel.org/r/20201203175756.1405564-1-thierry.reding@gmail.com Signed-off-by: Greg Kroah-Hartman

Revert "driver core: fw_devlink: Add support for batching fwnode parsing"

2020-12-09T18:10:20Z

This reverts commit 716a7a25969003d82ab738179c3f1068a120ed11. The fw_devlink_pause/resume() APIs added by the commit being reverted were a first cut attempt at optimizing boot time. But these APIs don't fully solve the problem and are very fragile (can only be used for the top level devices being added). This series replaces them with a much better optimization that works for all device additions and also has the benefit of reducing the complexity of the firmware (DT, EFI) specific code and abstracting out common code to driver core. Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20201121020232.908850-7-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

Revert "driver core: Remove check in driver_deferred_probe_force_trigger()"

2020-12-09T18:10:20Z

This reverts commit fefcfc968723caf93318613a08e1f3ad07a6154f. The reverted commit is fixing commit 716a7a259690 ("driver core: fw_devlink: Add support for batching fwnode parsing"). Since the original commit will be reverted, the fix can be reverted too. Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20201121020232.908850-5-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

Revert "driver core: Don't do deferred probe in parallel with kernel_init thread"

2020-12-09T18:10:20Z

This reverts commit cec72f3efc6272420c2c2c699607f03d09b93e41. Commit cec72f3efc62 ("driver core: Don't do deferred probe in parallel with kernel_init thread") was fixing a commit 716a7a259690 ("driver core: fw_devlink: Add support for batching fwnode parsing"). Since the commit being fixed itself is going to be reverted, the fix can also be reverted. Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20201121020232.908850-4-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

PM: runtime: Resume the device earlier in __device_release_driver()

2020-11-02T17:14:07Z

Since the device is resumed from runtime-suspend in __device_release_driver() anyway, it is better to do that before looking for busy managed device links from it to consumers, because if there are any, device_links_unbind_consumers() will be called and it will cause the consumer devices' drivers to unbind, so the consumer devices will be runtime-resumed. In turn, resuming each consumer device will cause the supplier to be resumed and when the runtime PM references from the given consumer to it are dropped, it may be suspended. Then, the runtime-resume of the next consumer will cause the supplier to resume again and so on. Update the code accordingly. Signed-off-by: Rafael J. Wysocki Fixes: 9ed9895370ae ("driver core: Functional dependencies tracking support") Cc: All applicable # All applicable Tested-by: Xiang Chen Reviewed-by: Greg Kroah-Hartman